The present invention relates generally to crop harvesting headers attachable to combines and, more particularly, to a basic header frame to which the cutterbar can be rigidly or flexibly attached.
Grain headers, having a cutterbar at the forward portion thereof along the entire width of the header, are generally constructed as either a rigid header or a flexible header. In a rigid header, the cutterbar is attached to the header frame such that there is generally no relative movement therebetween. The flexible header is constructed in such a manner as to permit the cutterbar to flex vertically relative to the header frame. This construction permits the flexible header to harvest crops, such as soybeans, which grow close to the ground, since the cutterbar is capable of vertical movement to follow the variations of the ground surface.
Usually, the cutterbar is of the reciprocating variety and includes a primary support bar, possibly in the shape of a right angle for rigidity or a flat bar for flexibility, along the entire width of the header. Attachment ribs interconnect the support bar and the header frame to attach the cutterbar to the header and provide either a flexible or rigid support. Basically, the frame for rigid and flexible headers are not interchangeable, as provision has to be made for pivotally mounting the attachment ribs if a flexible header is being constructed or for rigidly connecting the ribs to the header frame if a rigid header is desired.
This lack of interchangeability between header frames results in the need for more tooling and in a generally inefficient use of manpower, equipment and supplies, whenever the construction of both rigid and flexible headers is desired. Furthermore, the ability to convert from a rigid header to a flexible header, or vice versa is greatly restricted.